I find Jung very relevant to questions about Thelema. Jung's core purpose for the Work in depth Psychology was for Individuation. As I understand this, it is a shift in awareness that the Ego (our everyday, conscious 'I' thinking) is not the sum of who we really are. Integrating our unconscious hidden aspects and the conscious 'I' reunites us with our true Self. This I see this as similar to Thelema in finding your true Will so that your full potential as an individual star is unlocked.
I also see unification with your HGA to be another expression of this. I move between understanding my HGA as my Self, (higher as in higher than Ego) and as external. Maybe that is because the mind works like that - even in dreams external seeming figures work well as representations of our own thoughts. However, I am inclined to favour external more as it is easier to comprehend, is more emotional and captures my imagination.
From my (admittedly) little reading of Jung so far, I see a serious occultist and magician...
eta I think the questions you are raising are really thought provoking though they are rather huge topics to get a grasp on without a lot of areas to explore first. For me, even starting terms like Philosophy seem to be used in different ways....I thought Philosophy was just how you perceived the universe, self outlook on life etc, this seems to be different to academic Philosophy which looks like it has a more systematic way of thinking...
ps there is no fire.... no need to jump to any conclusions.... (though I do that too
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